For example, various designs of grommets for guiding cables or entire cable sets through an opening in a component are known in automotive engineering. This type of grommet is usually already attached to the cables and cable sets as part of the assembly process during manufacture of a cable set for a vehicle. For practical purposes this is done only after the cables have been cut to size and stripped of insulation, plug connectors have been attached and the cables or sets of cables have been bundled together. Cables or cable sets assembled in this way are then delivered to the vehicle manufacturers for installation in the vehicle with the grommet already attached. Here the grommet is arranged on the opening in the component of the vehicle, for instance to guide the cable or cable set from the engine compartment of a vehicle through the opening in the component, in this case a splash panel, and on into the vehicle interior. However, the component opening may also be situated in the frame of a vehicle door or any other part of the vehicle.
A grommet of this type is known from DE 10 2010 028 592 A1, for example. The grommet described therein is molded from two different foamed plastics. A first foamed plastic surrounds the cable and is connected in a material bond to a flange-like fastening body for attachment to an opening in a component. An additional foamed sealing body is provided as a seal for the component opening. Although this grommet allows a tight seal between the cable and the component opening, it has been shown that the production effort and expense involved are relatively high due to the structural design and the quantity of foamed plastic used.
Another grommet is described in DE 10 2010 039 225 A1. This grommet consists of foamed plastic as the sealing inner part, and a flange-like frame made of a different plastic and provided for attachment to a component opening. A disadvantage of this is that the production of the grommet is complicated due to the structural design and the quantity of foamed plastic used.
What the grommets known in the state of the art have in common is that they are manufactured mainly of foamed plastics with the aid of foam-molding tools. For this purpose the cables or cable sets are transported first to the foam-molding tool, inserted manually into the tool and removed, again manually, after the foamed plastic has cured. Here there is a risk of damage, for instance by crushing, to an already finished cable set as it is being transported to the foam-molding tool or during foaming, insertion or removal. As a consequence of this type of damage, the assembled cable set is rejected. Depending on the customer's wishes, the electrical functionality of the cable set is tested either before or after the foam molding of the grommet. In the case of testing before foam molding it is possible that damage to the cable set during the foam molding procedure would go unnoticed, at least up until delivery. In the case of testing after foaming it is possible that an additional test has been conducted before the rejection. On the whole, foam molding of the grommet involves risks. In addition, placing the cable or cable set into the foam-molding tool, curing the foamed plastic and subsequently removing the cable or cable set involves a comparatively long process time, frequently amounting to seven minutes or more. Furthermore, foam molding of plastics is expensive due to the large volume of foam required, since the purchase price of foamed plastic is comparatively high.
Moreover, in DE 37 40 582 A1, DE 10 2005 022 937 B4 and EP 0 731 000 B1, for example, grommets are known that have to be threaded onto the assembled cable set, which could lead to rejection due to damage occurring in the process.
In DE 297 21 749 U1 and U.S. Pat. No. 5,545,854 A, two-part grommets are known that are pressed onto the cable set from a lateral direction, so that threading them on becomes unnecessary. A disadvantage of this is that the force required to press on the grommet can also crush the cables. In addition, a tool is usually necessary to press on the grommet with the required amount of force.